This application claims the benefit of Korean Application No. 97-64071, filed Nov. 28, 1997, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an optical disc player, and more particularly to an apparatus for feeding a pick-up device in a radial direction of an optical disc.
2. Description of the Related Art
A Digital Versatile Disc (DVD) such as an optical disc is a recording medium for recording/reproducing information (data) into/from concentric tracks. Such an optical disc is loaded on a turntable by a disc loading device and is then rotated by a rotating device. While being rotated, an optical pick-up device travels in a radial direction of the optical disc and projects a laser beam onto the disc track. As a result, the information is recorded/reproduced to/from the disc.
FIG. 1 and FIG. 2 show a conventional optical pick-up feeding device for feeding an optical pick-up device 16. As it is shown, a spindle motor 12 is installed on an upper surface of a deck base having an opening 10a. The spindle motor 12 is provided with the turntable 14 by being mounted thereon.
In addition, the deck base 10 is installed with the optical pick-up feeding device thereon which feeds the optical pick-up device 16 in a radial direction of the optical disc (not shown). The optical pick-up feeding device includes a driving motor 18 installed at the side of the deck base 10, a lead screw 24 for feeding the optical pick-up device 16 by being rotated by the driving motor 18, and a guide shaft for guiding the optical pick-up device 16.
The lead screw 24 and the guide shaft 28 are installed on the deck base 10 by a plurality of fixing members 30 in such a manner that both are spaced in a parallel relationship with each other. The guide shaft 28 is fixed on the deck base 10 with both ends fixed by a plurality of the fixing members 30. And the lead screw 24 is fixed on the deck base 10 by a fixing member 30 fixing one end thereof. The lead screw 24 is rotated by a driving gear 20 mounted on an axis of the driving motor 18 and a driven gear 22 engaged with the lead screw 24. At this instance, the optical pick-up device 16 is fed along the guide shaft 28 in a radial direction of the optical disc from the opening 10a, while recording/reproducing the data to/from the optical disc. More specifically, a laser beam is projected from optical pick-up device 16. An optical axis of the laser beam should be in a vertical (perpendicular) relationship with respect to the surface of the optical disc which is loaded on the turn table 14.
However, in case the fixing members 30 on the deck base 10 are of wrong sizes, and/or the spindle motor 12 is assembled with error, the optical axis is deviated from the perpendicular relationship with the surface of the optical disc. Consequently, data can not be recorded/reproduced to/from the optical disc properly. Furthermore, in case the lead screw 24 and guide shaft 28 deviate from the state of parallelism, problems arise as the optical axis of the optical pick-up device 16 to be perpendicular with respect to the surface of the optical disc, and adjusting the parallelism of the guide shaft 28 in relation to the lead screw 24 is required.
In addition, a DC servo motor employed as a driving motor generates vibration when the optical pick-up device is fed. As a result, the optical pick-up device 16 cannot be precisely positioned at the expected position to access the optical disc.
The present invention has been provided to overcome the above problems, and accordingly, it is an object of the present invention to provide an optical pick-up feeding device for adjusting an optical axis of an optical pick-up device to be perpendicular with respect to a surface of an optical disc, and adjusting a parallelism of lead screw and guide shafts easily so that the feeding the optical pick-up device radially along the optical disc as well as recording/reproducing data to/from the optical disc are smoothly performed, vibration of the optical pick-up device generated while the latter is fed is reduced, and the optical pick-up device is positioned at the exact position to access the optical disc.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To achieve the above and other objects of the present invention, an optical pick-up feeding device including an optical pick-up device movably mounted on a deck base, a feeding section for feeding the optical pick-up device, a guiding section for guiding the optical pick-up device, and an adjusting section for adjusting an optical axis of the optical pick-up device to be a perpendicular relationship with respect to a surface of an optical disc.
The guiding section includes a pair of guide shafts connected to the optical pick-up device such that the optical pick-up device is fed therealong. The guide shafts are installed on the deck base while being spaced in parallel with each other by a predetermined distance.
The adjusting section includes adjusting holders rotatably installed on the deck base. The adjusting holders are formed with adjusting holes in spiral shape whereinto ends of the guide shafts are respectively inserted. Through the rotation of the adjusting holders, the guide shafts are raised or lowered.
The feeding section includes a lead screw engaged with a side of the optical pick-up device and a stepping motor for rotating the lead screw. The side of the optical pick-up device is engaged with the lead screw, and the optical pick-up device is fed by the rotation of the stepping motor.
According to an aspect of the present invention, the optical pick-up feeding device has advantages that the optical axis of optical pick-up device is easily adjusted to be perpendicular with respect to the surface of the optical disc while parallelism of the guide shafts is also adjusted easily. In addition, the optical pick-up device is not vibrated during the feeding process thereof, and is precisely fed to an expected position for access to the optical disc.